title: P-glycoprotein (ABCB1) expression in human skin is mainly restricted to dermal components.
abstract: Several transport proteins are constitutively expressed in skin cells, but the putative role of the ABC transporter P-glycoprotein (P-gp) in human skin is yet unknown. Therefore, we analysed mRNA and protein expression and localization of P-gp in human skin. Using qRT-PCR, we demonstrated a strong MDR1 mRNA expression in whole skin specimens and dermis, whereas the expression of MDR1 in epidermis, epidermal keratinocytes or dermal fibroblasts was only weak. Immunohistochemistry confirmed mRNA data and revealed a marked expression of P-gp within sweat ducts, vessels, nerve sheaths and muscles of human skin and a moderate expression in basal epidermis. Our findings closely correlate with previous studies in murine skin supporting the role of P-gp in the uptake of compounds from the epidermal compartment and their secretion into the bloodstream and sweat ducts. It may also prevent the uptake of xenobiotics into the skin by functioning as a barrier located in the dermal vasculature.
authors.forename: Claudia
authors.initials: C
authors.lastname: Skazik
authors.forename: Jörg
authors.initials: J
authors.lastname: Wenzel
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Marquardt
authors.forename: Arianna
authors.initials: A
authors.lastname: Kim
authors.forename: Hans F
authors.initials: HF
authors.lastname: Merk
authors.forename: David R
authors.initials: DR
authors.lastname: Bickers
authors.forename: Jens M
authors.initials: JM
authors.lastname: Baron
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics* / Q000378:metabolism*; D001808:Blood Vessels / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000378:metabolism; D002478:Cells, Cultured; D020405:Dermis / Q000378:metabolism*; D004817:Epidermis / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism; D015870:Gene Expression / Q000235:genetics*; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D009130:Muscle, Smooth / Q000378:metabolism; D009186:Myelin Sheath / Q000378:metabolism; D012867:Skin / Q000098:blood supply / Q000378:metabolism*; D012878:Skin Neoplasms / Q000378:metabolism; D013545:Sweat Glands / Q000378:metabolism
chemical_list: C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1